Double-underline-itis

From	BartC <bc@freeuk.com>
Newsgroups	comp.lang.c
Subject	Double-underline-itis
Date	2017-02-28 23:44 +0000
Organization	A noiseless patient Spider
Message-ID	<o951ti$ch6$1@dont-email.me> (permalink)

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I came across this declaration in some Linux header:

  extern int mbtowc (wchar_t *__restrict __pwc,
           const char *__restrict __s, size_t __n) __THROW;

There are thousands just the same. I can understand the double-underline 
prefix used for implementation names that may clash with those in the 
user namespace.

But what's with the double-underline on the parameter names? They 
shouldn't clash with anything. (And here, I assumed __pwc was yet 
another attribute that the implementation thinks is needed.)

Sometimes, as well as the double-underline at the start, they need to 
have one at the end too, such as '__restrict__' (what's wrong with just 
'restrict', if you need to have it all?).

Underlines are hard to see and tend to run together so you can't tell 
easily if there are two or three.

Since $ isn't used much, what would have been wrong with that? It's not 
pretty but at least you can see it!

-- 
bartc

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Double-underline-itis BartC <bc@freeuk.com> - 2017-02-28 23:44 +0000
  Re: Double-underline-itis supercat@casperkitty.com - 2017-02-28 15:54 -0800
  Re: Double-underline-itis Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-03-01 01:19 +0000
    Re: Double-underline-itis David Brown <david.brown@hesbynett.no> - 2017-03-01 09:11 +0100
    Re: Double-underline-itis BartC <bc@freeuk.com> - 2017-03-01 11:45 +0000
      Re: Double-underline-itis Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-03-01 12:30 +0000
        Re: Double-underline-itis BartC <bc@freeuk.com> - 2017-03-01 13:04 +0000
          Re: Double-underline-itis Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-03-01 15:29 +0000
            Re: Double-underline-itis gazelle@shell.xmission.com (Kenny McCormack) - 2017-03-01 15:47 +0000
          Re: Double-underline-itis Keith Thompson <kst-u@mib.org> - 2017-03-01 09:30 -0800
            Re: Double-underline-itis supercat@casperkitty.com - 2017-03-01 10:14 -0800
            Re: Double-underline-itis Tim Rentsch <txr@alumni.caltech.edu> - 2017-04-16 18:45 -0700

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